Amino Acids

Image credits: Associate Professor Terry Mulhern

Alanine/ Ala

A
Non-polar (Aliphatic)
Strong Helix formers

Cysteine/Cys

C
Polar, Uncharged, Thiol (-SH)
Forms Disulfide bridges in polypeptides

Aspartate/Asp

D
Polar, Negative, Acidic (-COO)

Glutamate/Glu

E
Polar, Negative, Acidic (-COO)

Phenylalanine/Phe

F
Aromatic (Benzene), Non-polar

Glycine/Gly

G
Non-polar (Aliphatic)
Helix breaker, R group does not contribute to helix stability

Histidine/His

H
Polar, Positive, Basic (NH3+)

Isoleucine/Ile

I
Non-polar (Aliphatic)

Lysine/Lys

K
Polar, Positive, Basic (NH3+)

Leucine/Leu

L
Non-polar (Aliphatic)
Strong Helix formers

Methionine/Met

M
Non-polar, Thioether
Can be air oxidised to sulfoxide

Asparagine/Asn

N
Polar, Uncharged

Proline/Pro

P
Non-polar (Aliphatic)
Helix breaker, lacks NH hydrogen bond donor

Glutamine/Gln

Q
Polar, Uncharged

Arginine/Arg

R
Polar, Positive, Basic (NH3+)

Serine/Ser

S
Polar, Uncharged

Threonine/Thr

T
Polar, Uncharged

Valine/Val

V
Non-polar (Aliphatic)

Tryptophan/Trp

W
Aromatic, Largely Non-polar, Indole Ring

Tyrosine/Tyr

Y
Aromatic, Largely Non-polar, -OH group